"He's going to have to learn how to mix his pitches," Callaway said. "It seems like he's kind of on a quick course to doing that. He's always been a guy that's made adjustments pretty good. I'm sure it will come along pretty quick for him."

Over 5 1/3 innings against Chicago, Salazar piled up eight strikeouts against one walk. He logged 48 fastballs, compared with 41 offspeed pitches. The 23 changeups were his most since he fired 26 in his big league debut, against Toronto on July 11. He also threw the most sliders (18) in any of his 10 starts.

Salazar threw 91 percent of his changeups for strikes and followed suit on 72 percent of his sliders.

"I've been working on my offspeed pitches," said Salazar, who has a 3.12 ERA and 65 strikeouts in 52 innings. "Finally, now, they're working better. I can use it more, my changeup and slider."

Callaway agrees.

"It's been better," he said. "Probably up to [Wednesday's start], he had been around 80 percent with his fastball. In that start he was around 55 percent. He mixed in all his pitches really well. If he can mix up his pitches like that, as good as those two pitches are, along with his dominant fastball, he's going to have pretty good success."